The present invention broadly relates to a new and improved device for winding-up a thread or yarn or the like to form a yarn package on a rotatable conical bobbin tube or the like by means of a rotatable drive roller.
Generally speaking, the device for winding-up filamentary materials, such as a thread or yarn or the like to form a yarn package on a rotatable conical bobbin tube by means of a rotatable drive roller or roll comprises substantially cylindrical rotational elements arranged axially adjacent to one another on a common drive shaft. The central or intermediate rotational element of these rotational elements is fixedly secured to the drive shaft and at each end of this central or intermediate rotational element there is arranged a lateral rotational element on a respective therewith operatively associated rotational bearing located on the drive shaft. The rotational elements contactingly engage with the bobbin tube or yarn package formed thereon, as the case may be, along a contact line or generatrix for rolling engagement therewith during the yarn wind-up operation. The lateral rotational elements are connected together or interconnected by a differential transmission.
Such a device is already known from European Patent Publication No. 63,690. In accordance with the device shown and described in that patent, friction and rubbing of the drive roller or roll on the yarn packages is strongly reduced and a wound-up yarn is obtained with even yarn tension.
However, it has been found in practice that the lateral rotational elements provided in accordance with such European Patent Publication No. 63,690 can jam with the central rotational element. The main cause of such jamming is that contamination or soiling can arise between the central rotational element and the lateral rotational elements as a result of the accumulation therebetween of fibers, yarn particles, dust and the like. If jamming arises, one of these lateral rotational elements rotates with a too high or a too low rotational speed and forces the other lateral rotational element to rotate with a too low or a too high rotational speed, as the case may be, since the two lateral rotational elements are fixedly secured to each other. Under such conditions, the drive roll exerts a pronounced rubbing effect or scuffing action on the yarn package to be wound, so that damage to the yarn or the like can arise.
In the event of such jamming, an attempt is generally made to free the system by forced rotation of the blocked cylinder or rotational element. Since, in the known drive rolls, the gear wheels of the differential transmission are made from plastic material for several reasons, there exists a further disadvantage in that during such forced rotation of the blocked cylinder or rotational element, due to a false manipulation the non-jammed or non-blocked lateral cylinder or rotational element can also be fixedly grasped by the operator or repair work person upon holding of the drive roll. As a result, the teeth of the gear wheels of the differential transmission are often broken.